From: nuny@bid.nes   
      
   On Saturday, March 11, 2017 at 10:09:55 AM UTC-8, MrAnderson wrote:   
   > Hi, what do you think would be the best speed for projectiles launched from   
   > coilguns in setting where engagements usually happen at a few thousand   
   > kilometer range?   
      
     Right now, both coilgun and railgun performance appears to be hovering   
   around 5 km/sec or so, meaning several hundred seconds time-to-target. That's   
   way too slow for exciting broadside exchanges. ;>)   
      
     The Wiki article says a Russian researcher got a 2 gram projectile to 5 km/s   
   in a single-stage gun only 1 cm long in 1978, so it's reasonable to expect   
   more bang per greater length, but recoil is in line with the shot, not   
   perpendicular as in railguns.   
      
     I don't know of any pure physics-based obstacles to obtaining    
   ulti-thousands of km/sec velocities (given enough power available and adequate   
   heat management, "mere engineering details"), yielding one second or so   
   time-to-target at your desired ranges.   
      
     There's not much point in a spacecraft trying to "shoot down" such   
   projectiles Aegis-style, so armor is the next usually assumed best defense,   
   but how do you defeat say a dozen kg of DU at 1000 km/sec? You duck, that's   
   how.   
      
     Assuming targets can't defeat such projectiles with armor, I think the major   
   concern is "how fast can targets jink out of the way once they detect incoming   
   projectiles?" So, how massive and how sturdy are your ships?   
      
      
     Mark L. Fergerson   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)